1. Field of the Invention
This invention relates to a retractable cover or curtain for a greenhouse and specifically to a top furling automated retractable cover or curtain for a greenhouse that retracts onto two rolls, each adjacent to and parallel to the ridge line of the roof and the greenhouse.
2. Description of Related Art
A greenhouse is a building in which plants are grown. Growing plants in a building is advantageous because the interior of a building can be sheltered from the exterior to allow for easier climate control of the interior in a manner that is more conducive to plant growth. Typically, the roof and walls of a greenhouse are made of impermeable and transparent or translucent material. The transparent or translucent aspect of the material allows light and energy from the sun to penetrate the roof and walls of the greenhouse in order to shine light and energy onto the plants and interior of the greenhouse. Light and energy are used to grow the plants as is required with the photosynthesis process and are also used to heat the interior of the greenhouse as light and energy are absorbed by the plants and interior of the greenhouse to radiate heat inside the greenhouse. The impermeable aspect of the material acts to shelter the plants and interior of the greenhouse from outside weather such as wind, rain, sleet, snow, and the like, to retain the radiated heat from the interior of the greenhouse, and to retain evaporated water vapor within the interior of the greenhouse for plant watering recycling.
There are instances where it is desirable to extend a special cover or curtain over the existing impermeable and transparent or translucent material of a greenhouse. When exterior temperatures are lower than optimal for plant growth, an insulated cover can be used to help retain more heat within the interior of the greenhouse, thereby keeping optimal growth temperatures for longer periods of time. When exterior temperatures are higher than optimal for plant growth, a solar shade cover can be used to block or reduce the amount of light and energy passing into the interior of the greenhouse, which in turn helps reduce the interior temperature of the greenhouse. In order to control the growth stage of the plants, a completely opaque cover can be used to block out all light and energy from passing through the greenhouse at certain times of day to artificially change the length of day perceived by the plants, which designates certain growth cycles within the plants.
There also instances where it is desirable to retract the special cover or curtain from covering the greenhouse and/or to retract the existing impermeable and transparent or translucent material from covering the greenhouse. When the interior temperatures of the greenhouse are higher than optimal, the insulated cover can be removed to help release more heat from the interior of the greenhouse, thereby keeping optimal growth temperatures for longer periods of time. When the interior temperatures of the greenhouse are lower than optimal, the solar shade cover can be removed to increase the amount of light and energy passing into the interior of the greenhouse, which in turn helps increase the interior temperature of the greenhouse. In order to provide maximum air ventilation for the plants, all coverings and barriers could be removed from the roof and walls of the greenhouse. In order to provide maximum heat loss through radiation into the outside air, all coverings and barriers could be removed from the roof and walls of the greenhouse.
This invention is a retractable greenhouse cover that can be used to reversibly extend a cover or curtain over the roof and sidewalls of a greenhouse in order to provide an insulated cover and/or a solar shade cover for the greenhouse. In addition, the retractable greenhouse cover of this invention can be used to reversibly extend the impermeable and transparent or translucent material over the frame of the greenhouse in order to install and retract all covering from the roof and sidewalls of the greenhouse. There are other retractable greenhouse covers in the prior art, but none that use a top-furling dual-awning mechanism that can reversibly extend any type of cover or curtain material over the roof and sidewalls of a greenhouse as shown and described here.